Title of Invention

A SYSTEM FOR AND A METHOD OF CONTROLLING A THROTTLE DURING A VIRTUAL BUMPER EVENT

Abstract A control system for controlling a throttle of a vehicle during a virtual bumper event is provided. The system includes: an enable module that selectively enables torque reduction based on at least one of a torque reduction request and an object detection signal; a throttle override module that overrides a pedal request by commanding a throttle position to reduce torque when the torque reduction is enabled; and a throttle learn module that commands the throttle position to gradually increase torque based on a position indicated by the pedal request when torque reduction is no longer enabled.
Full Text GP-307436-PTE-CD
1
VIRTUAL BUMPER THROTTLE CONTROL ALGORITHM
FIELD
[0001] The present invention relates to methods and systems for
controlling a throttle of a vehicle.
BACKGROUND
[0002] The statements in this section merely provide background
information related to the present disclosure and may not constitute prior art.
[0003] Virtual bumper systems employ the use of several sensors
mounted across a front and/or rear bumper of a vehicle. The sensors detect an
object within a projected path of the vehicle. Both visual and audible warnings
can be signaled to the driver to indicate a detected object. In addition, the brakes
and the powertrain can be controlled to reduce the likelihood of a collision. More
particularly, the brakes can be automatically applied and engine torque can be
automatically reduced. Automatic braking and automatic torque reduction can be
controlled independently. Typically the torque reduction is performed before the
automatic braking to prevent the powertrain from interfering with the braking.
[0004] The application of the brakes may be intentionally controlled to
be fairly abrupt. The abrupt automatic braking generally results in a driver's initial
reaction to manually apply the brake pedal, thereby reinforcing the operation of
the virtual bumper system. The throttle should be controlled to manage engine
torque before, during, and after the application of the brakes. Ineffective control
of the throttle can cause undesirable surges in engine torque.
SUMMARY
[0005] Accordingly, a control system for controlling a throttle of a
vehicle during a virtual bumper event is provided. The system includes: an
enable module that selectively enables torque reduction based on at least one of
a torque reduction request and an object detection signal; a throttle override
module that overrides a pedal request by commanding a throttle position to
reduce torque when the torque reduction is enabled; and a throttle learn module

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that commands the throttle position to gradually increase torque based on a
position indicated by the pedal request when torque reduction is no longer
enabled.
[0006] In other features, a method of controlling a throttle during a
virtual bumper event is provided. The method includes: receiving a torque
reduction request; processing a pedal request corresponding to a position of an
accelerator pedal; setting a pedal minimum equal to a predetermined maximum;
and commanding a throttle position based a difference between the pedal
request and the pedal minimum.
[0007] Still in other features, a method of controlling a throttle during
virtual bumper events is provided. The method includes: receiving a virtual
bumper request to operate the throttle in an override mode; operating the throttle
in an override mode by commanding the throttle to a closed position based on the
request; and transitioning out of the override mode by commanding the throttle
back to an open position, gradually based on a pedal request and a throttle learn
method when the torque request is no longer received.
[0008] Further areas of applicability will become apparent from the
description provided herein. It should be understood that the description and
specific examples are intended for purposes of illustration only and are not
intended to limit the scope of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The drawings described herein are for illustration purposes only
and are not intended to limit the scope of the present disclosure in any way.
[0010] Figure 1 is a functional block diagram of a vehicle having a
virtual bumper system.
[0011] Figure 2 is a dataflow diagram illustrating a virtual bumper
control system.
[0012] Figure 3 is a dataflow diagram illustrating a virtual bumper
throttle control system.
[0013] Figure 4 is a flowchart illustrating a virtual bumper throttle
control method of the virtual bumper control system.

GP-307436-PTE-CD
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[0014] Figure 5 is a flowchart illustrating a throttle override control
method.
[0015] Figure 6 is a flowchart illustrating a throttle learn method.
DETAILED DESCRIPTION
[0016] The following description is merely exemplary in nature and is
not intended to limit the present disclosure, application, or uses. It should be
understood that throughout the drawings, corresponding reference numerals
indicate like or corresponding parts and features. As used herein, the term
module refers to an application specific integrated circuit (ASIC), an electronic
circuit, a processor (shared, dedicated , or group) and memory that execute one
or more software or firmware programs, a combinational logic circuit and/or other
suitable components that provide the described functionality. As used herein, the
phrase at least one of A, B, and C should be construed to mean a logical (A or B
or C), using a non-exclusive logical or. It should be understood that the disclosed
methods may be executed in different forms without altering the principles of the
present invention.
[0017] Referring now to Figure 1, a vehicle 10 includes an engine 12,
that combusts an air and fuel mixture within cylinders (not shown) to produce
drive torque. Air is drawn into the engine 12 through a throttle 14. A torque
converter 16 transfers and multiplies torque from the engine 12 to a transmission
18. The transmission 18 includes one or more gear sets that transfer torque to a
driveline 20 based on a desired speed.
[0018] An accelerator pedal 22 enables a driver of the vehicle 10 to
adjust the position of the throttle 14 to achieve a desired torque. An accelerator
pedal position sensor 24 generates a pedal signal (PEDALREQUEST) indicating a
position of the accelerator pedal 22. A control module 26 receives the pedal
signal and adjusts the position of the throttle 14 accordingly. An initial position of
the accelerator pedal 22 (zero percent) can be used to electronically control the
throttle 14 to a closed position, thereby reducing the quantity of air drawn into the
engine 12. As the accelerator pedal 22 is adjusted from the initial position, the
throttle 14 gradually opens to increase the quantity of air delivered to the engine

GP-307436-PTE-CD
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12. The control module 26 adjusts fuel based on the airflow. As a greater
amount of air and fuel is delivered to the engine 12, the drive torque increases.
[0019] Similarly, a brake pedal 28 allows the driver to enable a braking
system 40. The braking system 40 applies a braking torque to wheels 34 and/or
the driveline 20 to counter the engine torque. A brake pedal sensor 30 senses
the position of the brake pedal 28 and generates a brake pedal signal
accordingly. The control module 26 receives the signal and controls the braking
system 40 of the vehicle 10. A vehicle speed sensor 32 senses a rotational
speed of a wheel 34 and generates a vehicle speed signal accordingly. The
control module 26 computes a vehicle speed from the vehicle speed signal.
[0020] The vehicle 10 includes a virtual bumper system. The virtual
bumper system includes one or more object sensors 36, 38 that are fixed to a
front and/or rear bumper of the vehicle 10. The object sensors 36, 38 sense
objects in front of or in back of the vehicle 10 using motion, light, or other sensing
methods. As the vehicle 10 moves, the object sensors 36, 38 generate a
detection signal based on objects detected within the current estimated path.
[0021] The control module 26 receives the detection signal and controls
the engine 12, the throttle 14, and/or the brake system 40 accordingly. More
particularly, when the vehicle 10 is traveling below a predetermined speed and an
object is detected, the control module 26 controls airflow and fuel such that less
torque is generated and controls the brake system 40 in an attempt to decelerate
the vehicle 10. The reduction in torque and the application of the brakes is
performed in an effort to reduce the vehicle speed. Once the object is no longer
detected and control exits the throttle control method (as will be discussed further
below), the control module 26 resumes control of the engine 12, the throttle 14,
and the brake system 40 according to conventional methods.
[0022] Referring now to Figure 2, a control module 26 including a
virtual bumper throttle control system is shown. As can be appreciated, the
functionality of the control module 26 can be partitioned into one or more control
modules. For example, a separate engine control module, a separate virtual
bumper control module, and a separate brake control module can be
implemented. In this instance, data is communicated between the control

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modules via one or more known vehicle communication protocols. It is also
appreciated that the functionality can be partitioned into one or more sub-
modules embedded within particular control modules. For ease of the
discussion, the remainder of the disclosure will be discussed in the context of a
single control module 26 for controlling all features of the vehicle 10 and including
the virtual bumper throttle control.
[0023] As shown in Figure 2, the control module 26 includes an object
detection module 50, a torque control module 52, a brake control module 54, and
a throttle control module 56. As can be appreciated, the modules shown may be
combined and/or further partitioned to similarly provide virtual bumper control. As
can be appreciated, inputs to the control module 26 can be sensed from the
vehicle 10, received from other control modules (not shown) within the vehicle 10,
or determined by other sub-modules within the control module 26. The object
detection module 50 receives as input a detection signal 58 and vehicle speed
60. When the vehicle 10 is traveling below a predetermined vehicle speed
threshold and an object is detected to be within the vehicle's estimated path, a
detection flag 62 is set to TRUE. Otherwise, the detection flag 62 remains
FALSE. The torque control module 52 receives as input the detection flag 62.
The torque control module 52 determines a torque reduction request 64 based on
the detection flag 62, a determined time-to-collision, and an evaluation of a time
threshold for engine torque reduction.
[0024] The throttle control module 56 receives as input the torque
reduction request 64, an accelerator pedal request 68, and vehicle speed 60.
The throttle control module 56 controls the throttle 14 (Figure 1) via a throttle
command 70 according to a virtual bumper throttle control method as will be
discussed further below. The brake control module 54 receives as input the
torque reduction request 64. Based on the torque reduction request 64, the
brake control module 54 controls the brake system 40 (Figure 1) via a brake
command 66. The timing of the brake command 66 and the throttle command 70
are controlled such that the throttle control does not interfere with the brake
control.

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[0025] Referring to Figure 3, a dataflow diagram illustrates the virtual
bumper throttle system in more detail. The throttle control module 56 includes
an enable module 72, a throttle override module 76, a pedal override module 78,
and a throttle learn module 80. As can be appreciated, the modules shown may
be combined and/or further partitioned to similarly control the throttle 14 (Figure
1) during a virtual bumper event. The enable module 72 receives as input vehicle
speed 60 and the torque reduction request 64. Based on vehicle speed 60 and
the torque reduction request 64, the enable module 72 sets an enable flag 76 to
enable torque reduction. The throttle override module 76 overrides the pedal
request 68 and commands throttle position 70 to allow for the torque reduction
when the enable flag 82 indicates a torque reduction is desired.
[0026] The pedal override module 78 detects a pedal override initiated
by the operator of the vehicle 10. If the pedal request 68 is greater than a
predetermined threshold, the pedal override module 78 sets an override value X
84 in order to learn the throttle position back to the position requested by the
pedal request 68. The override value X 84 can be gradually updated according
to a rate limiting function or a lag filter. The throttle override module 76
commands the throttle position based on the override value X even while the
enable flag 82 indicates a torque reduction is desired. The throttle learn module
80 determines a learn value Y 86 in order to learn the throttle position back to the
pedal request 68. The learn value Y 86 can be gradually updated according to a
rate limiting function or a lag filter. The throttle override module 76 commands
the throttle position based on the learn value Y 86 when the enable flag indicates
that the torque reduction is no longer desired.
[0027] Referring to Figure 4, a flowchart illustrates various
embodiments of the virtual bumper throttle control method of the throttle control
module 56 of Figure 3. The throttle control method can be run continually during
engine operation. In various embodiments, the virtual bumper throttle control
method releases the throttle control from being controlled by the accelerator
pedal request during virtual bumper events, allows for the driver to override the
throttle control, and allows for a smooth transition back to controlling the throttle
based on the accelerator pedal request after the virtual bumper event. The

GP-307436-PTE-CD
7
method can be initiated based on the detection flag 62 of Figure 2. In various
other embodiments, the method can be initiated based on the torque reduction
request 64 as shown in Figures 2 and 3.
[0028] More particularly, if the vehicle speed is below a predetermined
threshold at 100 and a torque reduction request is received at 102, control
overrides the throttle control at 104 as will be discussed in more detail below. A
reduction previous flag is set to TRUE at 106. Control loops back and continues
to override the throttle control while the vehicle speed is below the threshold and
the torque reduction request is received. If the vehicle speed is below the
predetermined threshold at 100 and the torque reduction request is no longer
received at 102 but the reduction previous flag is TRUE at 112, control transitions
out of the throttle override control. If during the transition the accelerator pedal
request indicates that the pedal is released at 114, conventional throttle control is
resumed at 116. If during the transition the accelerator pedal request indicates
that the pedal is partially depressed, control applies a learning strategy to
transition throttle control back to conventional throttle control as will be discussed
in more detail below. The reduction previous flag is reset to FALSE at 120.
Thereafter, control loops back and continues to monitor vehicle speed and torque
reduction requests at 100 and 102 respectively.
[0029] Referring now to Figure 5, a method of overriding the throttle
control is shown. The method can be performed by control at process box 104
of Figure 4. The accelerator pedal request is processed at 200. If the
accelerator pedal request is less than or equal to a pedal override threshold at
202 a pedal minimum value is set to a predetermined maximum at 204. In
various embodiments, the maximum is equal to one hundred percent. Control
sets an indicated pedal to the pedal request minus the pedal minimum at 206.
Setting the pedal minimum equal to one hundred percent forces the indicated
pedal to zero. Control then commands throttle based on the indicated pedal at
208. If, at 202, the accelerator pedal request is greater than the pedal override
threshold, the pedal minimum is set equal to X. In various embodiments, the
override threshold is a predetermined value between seventy-five and one
hundred percent. This allows the driver to override the throttle control. X allows

GP-307436-PTE-CD
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the indicated throttle to be increased to or near the pedal request. In various
embodiments, X can be determined based on at least one of a rate limiting
function and a lag filter. Control returns to set the reduction previous flag to
TRUE at 106 of Figure 4.
[0030] Referring now to Figure 6, a throttle learn method is shown. The
method is performed by control at process box 118 of Figure 4. The accelerator
pedal request is processed at 300. The pedal minimum value is set to a
determined value Y at 302. Y allows the indicated throttle to be gradually
increased back to the accelerator pedal request. In various embodiments, Y can
be determined based on at least one of a rate limiting function and a lag filter.
Control sets the indicated pedal to the accelerator pedal request minus the pedal
minimum at 304. Control then commands throttle based on the indicated pedal at
306. If, at 308, the accelerator pedal request equals the indicated pedal, control
returns to resume throttle control based on the accelerator pedal request at 120
of Figure 4. Otherwise, if the indicated pedal does not equal the accelerator
pedal request, then control loops back and continues to gradually increase the
indicated pedal back to the accelerator pedal request.
[0031] As can be appreciated, all comparisons made in the methods
above can be implemented in various forms depending on the selected values for
comparison. For example, a comparison of "greater than" may be implemented
as "greater than or equal to" in various embodiments. Similarly, a comparison of
"less than" may be implemented as "less than or equal to" in various
embodiments
[0032] Those skilled in the art can now appreciate from the foregoing
description that the broad teachings of the present disclosure can be
implemented in a variety of forms. Therefore, while this invention has been
described in connection with particular examples thereof, the true scope of the
invention should not be so limited since other modifications will become apparent
to the skilled practitioner upon a study of the drawings, the specification and the
following claims.

GP-307436-PTE-CD
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CLAIMS
What is claimed is:
1. A control system for controlling a throttle of a vehicle during a virtual
bumper event, comprising:
an enable module that selectively enables torque reduction based
on at least one of a torque reduction request and an object detection signal;
a throttle override module that overrides a pedal request by
commanding a throttle position to reduce torque when the torque reduction is
enabled; and
a throttle learn module that commands the throttle position to
gradually increase torque based on a position indicated by the pedal request
when torque reduction is no longer enabled.
2. The control system of claim 1 wherein the throttle learn module
commands the throttle position to gradually increase torque based on at least one
of a rate limiting function and a lag filter function.
3. The control system of claim 1 further comprising a pedal override
module that detects a pedal override based on a comparison of the pedal request
and a predetermined threshold and that commands the throttle position to
gradually increase torque based on the pedal request when a pedal override is
detected.
4. The control system of claim 3 wherein the pedal override module
commands the throttle position to gradually increase torque based on at least one
of a rate limiting function and a lag filter function.
5. The control system of claim 3 wherein the pedal override module
commands the throttle position to gradually increase torque while torque
reduction is enabled.

GP-307436-PTE-CD
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6. The control system of claim 1 wherein the enable module enables
torque reduction based on vehicle speed.
7. The control system of claim 1 wherein the throttle override module
commands the throttle to a closed position when torque reduction is enabled.
8. The control system of claim 1 wherein the throttle learn module
commands the throttle to gradually open based on the pedal request.
9. A method of controlling a throttle during a virtual bumper event,
comprising:
receiving a torque reduction request;
processing a pedal request corresponding to a position of an
accelerator pedal;
setting a pedal minimum equal to a predetermined maximum; and
commanding a throttle position based a difference between the
pedal request and the pedal minimum.
10. The method of claim 9 further comprising setting the pedal
minimum based on a rate limiting function when the pedal request is greater than
an override threshold.
11. The method of claim 9 further comprising setting the pedal
minimum based on a lag filter function when the pedal request is greater than an
override threshold.
12. The method of claim 9 further comprising commanding the throttle
position based on the pedal request after the pedal request indicates that the
pedal is in an initial position and the torque reduction request is no longer
received.

GP-307436-PTE-CD
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13. The method of claim 9 further comprising commanding the throttle
position based on at least one of a rate limiting function and a lag filter function
when the pedal request indicates that the pedal is in a depressed position and
the torque reduction request is no longer received.
14. A method of controlling a throttle during virtual bumper events,
comprising:
receiving a virtual bumper request to operate the throttle in an
override mode;
operating the throttle in an override mode by commanding the
throttle to a closed position based on the request; and
transitioning out of the override mode bycommanding the throttle
back to an open position, gradually based on a pedal request and a throttle learn
method when the torque request is no longer received.
15. The method of claim 14 further comprising evaluating vehicle speed
and wherein the operating the throttle in an override mode occurs when the
vehicle speed is below a predetermined threshold.
16. The method of claim 14 wherein the throttle learn method is based
on a rate limiting function.
17. The method of claim 14 wherein the throttle learn method is based
on a lag filter function.
18. The method of claim 14 further comprising commanding the throttle
back to an open position based on a throttle learn method when a pedal request
exceeds a threshold and when the torque request is received.

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19. The method of claim 18 wherein the throttle learn method is based
on a rate limiting function.
20. The method of claim 18 wherein the throttle learn method is based
on a lag filter function.

A control system for controlling a throttle of a vehicle during a virtual
bumper event is provided. The system includes: an enable module that
selectively enables torque reduction based on at least one of a torque reduction
request and an object detection signal; a throttle override module that overrides a
pedal request by commanding a throttle position to reduce torque when the
torque reduction is enabled; and a throttle learn module that commands the
throttle position to gradually increase torque based on a position indicated by the
pedal request when torque reduction is no longer enabled.

Documents:

01212-kol-2007-abstract.pdf

01212-kol-2007-assignment.pdf

01212-kol-2007-claims.pdf

01212-kol-2007-correspondence others 1.1.pdf

01212-kol-2007-correspondence others 1.2.pdf

01212-kol-2007-correspondence others 1.3.pdf

01212-kol-2007-correspondence others.pdf

01212-kol-2007-description complete.pdf

01212-kol-2007-drawings.pdf

01212-kol-2007-form 1.pdf

01212-kol-2007-form 18.pdf

01212-kol-2007-form 2.pdf

01212-kol-2007-form 3.pdf

01212-kol-2007-form 5.pdf

01212-kol-2007-priority document.pdf

1212-KOL-2007-(03-01-2012)-ABSTRACT.pdf

1212-KOL-2007-(03-01-2012)-CLAIMS.pdf

1212-KOL-2007-(03-01-2012)-CORRESPONDENCE.pdf

1212-KOL-2007-(03-01-2012)-DESCRIPTION (COMPLETE).pdf

1212-KOL-2007-(03-01-2012)-DRAWINGS.pdf

1212-KOL-2007-(03-01-2012)-FORM-1.pdf

1212-KOL-2007-(03-01-2012)-FORM-2.pdf

1212-KOL-2007-ABSTRACT-1.1.pdf

1212-KOL-2007-ABSTRACT.pdf

1212-KOL-2007-AMANDED CLAIMS-1.1.pdf

1212-KOL-2007-AMANDED CLAIMS.pdf

1212-KOL-2007-ASSIGNMENT.pdf

1212-KOL-2007-CORRESPONDENCE 1.2.pdf

1212-KOL-2007-CORRESPONDENCE OTHERS 1.4.pdf

1212-KOL-2007-CORRESPONDENCE-1.1.pdf

1212-KOL-2007-CORRESPONDENCE.pdf

1212-KOL-2007-DESCRIPTION (COMPLETE)-1.1.pdf

1212-KOL-2007-DESCRIPTION (COMPLETE).pdf

1212-KOL-2007-DRAWINGS-1.1.pdf

1212-KOL-2007-DRAWINGS.pdf

1212-KOL-2007-EXAMINATION REPORT.pdf

1212-KOL-2007-FORM 1-1.1.pdf

1212-KOL-2007-FORM 1.pdf

1212-KOL-2007-FORM 18.pdf

1212-KOL-2007-FORM 2-1.1.pdf

1212-KOL-2007-FORM 2.pdf

1212-KOL-2007-FORM 26.pdf

1212-KOL-2007-FORM 3 1.1.pdf

1212-KOL-2007-FORM 3.pdf

1212-KOL-2007-FORM 5.pdf

1212-KOL-2007-GRANTED-ABSTRACT.pdf

1212-KOL-2007-GRANTED-CLAIMS.pdf

1212-KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

1212-KOL-2007-GRANTED-DRAWINGS.pdf

1212-KOL-2007-GRANTED-FORM 1.pdf

1212-KOL-2007-GRANTED-FORM 2.pdf

1212-KOL-2007-GRANTED-LETTER PATENT.pdf

1212-KOL-2007-GRANTED-SPECIFICATION.pdf

1212-KOL-2007-OTHERS 1.2.pdf

1212-KOL-2007-OTHERS-1.1.pdf

1212-KOL-2007-OTHERS.pdf

1212-KOL-2007-PETITION UNDER RULE 137.pdf

1212-KOL-2007-REPLY TO EXAMINATION REPORT 1.1.pdf

1212-KOL-2007-REPLY TO EXAMINATION REPORT.pdf

abstract-01212-kol-2007.jpg


Patent Number 252209
Indian Patent Application Number 1212/KOL/2007
PG Journal Number 18/2012
Publication Date 04-May-2012
Grant Date 01-May-2012
Date of Filing 31-Aug-2007
Name of Patentee GM GLOBAL TECHNOLOGY OPERATIONS, INC
Applicant Address 300 GM RENAISSANCE CENTER DETROIT, MICHIGAN
Inventors:
# Inventor's Name Inventor's Address
1 PAUL A. BAUERLE 7778 CLYDE ROAD FENTON, MICHIGAN 48430
2 PATRICK J. O'LEARY 19405 APPLE CREEK CLINTON TOWNSHIP, MICHIGAN 48038
PCT International Classification Number F02D11/10; F02D41/00; F02D11/10
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/530,584 2006-09-11 U.S.A.